1. Field of the Invention
The present invention relates to an apparatus for the continuous and direct measurement of the temperature of the sea in its upper superficial part.
The temperature of the surface of a lake or other water surfaces may also be directly detected with such apparatus.
2. Prior Art
One method used in practice for the detection of a water surface temperature is infrared radiometry, but by this means only the remote temperature of the external face of the water is measured. Such a measurement may not be considered to be exact owing to the reflection of sun light, the atmospheric layer to be traversed, possible fog, etc. Other sea water surface measurements being carried out in practice only measure the average temperature of the first half meter of water.
A knowledge of the thermal exchange between water and the atmosphere across the upper thin ultra superficial layer of water, whose thickness is of the order of a fraction of a millimeter, is very important and the precision of the measurement must be at least of the order of 10.sup.-1 .degree. C.
Various sea surface temperature measuring apparatuses are known--see, for example, U.S. Pat. Nos. 3,670,572 and 3,596,512 and French Pat. No. 2,330,410--but these are generally not adapted to measure specifically the temperature of the upper superficial layer of a water surface, which is particularly important for the infrared teledetection of temperature.